Those skilled in the art are well aware of the technological importance of chelating agents for removing metal ions from various effluents, such as waste water, plating baths and the like. Chelating agents provide means of manipulating and controlling metal ions by forming complexes that usually have properties that are markedly different from those of the original metal ions or the chelators. These properties may serve to reduce undesirable effects of metal ions in drinking water, waste water, sewage and the like.
In this regard, many industries utilize heavy metals and/or rare earth metals in their manufacturing processes. Such use typically results in liquid (generally aqueous) waste streams that contain residues of the rare earth or heavy metals utilized in the given manufacturing process. For example, the waste stream resulting from electronics, electroplating and photographic processes typically contain metal ions such as copper, nickel, zinc, chromium, cadmium, aluminum, lead, antimony, silver and gold, amongst others in aqueous solutions accompanied by various anions such as sulfate, chloride, fluoroborate and cyanide. Because of the potential adverse effects of such metals on health and the environment, the removal of rare earth metals and heavy metal ions from aqueous waste streams is a problem of continuing significance. There is a growing need in the relatively new area of environmentally benign chemistry to design organic ligands in order to selectively remove and recover environmentally and economically important metal ions from aqueous solution.
Furthermore, the relationship of ligand structure to the chemical and physical properties of derived metal complexes is a central theme in such vital and disparate fields as selective catalysis, treatments for heavy metal poisoning, sensor discovery, and bioinorganic chemistry. The numerous advances made in these fields highlight the utility of complexes with well-designed structural, electronic and/or stereochemical features. However, the rational design of such complexes remains extremely challenging, especially if novel physical and chemical properties are sought. In this context, a systematic method for the expedient generation of new classes of coordination complexes would clearly be of great value.
The present invention provides methods and compositions, i.e. synthetic libraries of binding moities, for identifying compounds which bind to a metal atom. The subject method comprises (a) chemically synthesizing a variegated library of potential binding moieties (xe2x80x9cPBMsxe2x80x9d), and (b) screening the library of PBMs to isolate/identify those members that bind to a metal atom, or to non-metal atoms, e.g., cationic, anionic and even neutral molecules. Utilizing such combinatorial chemistry techniques as, e.g., direct characterization, encoding, spatially addressing and/or deconvolution, the molecular identity of individual members of the PBM library can be ascertained in a screening format.
Another aspect of the present invention pertains to kits for carrying of the instant method.
Still another aspect of the present invention provides compositions including one or more of the PBM compounds identified by the instant method.